Hydraulic systems and methods comprising a source of hydraulic pressure; a hydraulic load; and an energy recovery circuit. The source of hydraulic pressure is fluidly connected to the hydraulic load through a first hydraulic channel with an orifice. The energy recovery circuit includes a recovery channel which is fluidly connected at its first end to the orifice on the side of it which is connected to the source of hydraulic pressure, and which is fluidly connected at its second end to a hydraulic motor.

Hydraulic systems and methods comprising a source of hydraulic pressure; a hydraulic load; and an energy recovery circuit. The source of hydraulic pressure is fluidly connected to the hydraulic load through a first hydraulic channel with an orifice. The energy recovery circuit includes a recovery channel which is fluidly connected at its first end to the orifice on the side of it which is connected to the source of hydraulic pressure, and which is fluidly connected at its second end to a hydraulic motor.

This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism and a boom cylinder The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to starting and stopping of the rotary mechanism. A control system configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, and a boom control valve configured to control the boom cylinder through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

An example valve includes: a plurality of ports comprising: a first port, a second port, and a third port; a spool configured to block fluid flow from the first port to the third port while allowing fluid flow from the third port to the second port when the valve is in an unactuated state; a spring applying a biasing force on the spool in a proximal direction, wherein when the valve is actuated, the spool moves in a distal direction against the spring, thereby allowing fluid flow from the first port to the third port while blocking fluid flow from the third port to the second port; and a turbine configured to rotate as fluid flows from the first port to the third port when the valve is in an actuated state.

A closed-loop hydraulic circuit associated with a swing mechanism of a machine is controlled to obtain both a pressure control during acceleration and deceleration of the swing mechanism and a velocity control during coasting. In this manner, a system pressure in closed-loop hydraulic circuit is maintained below a maximum allowable pressure during acceleration and deceleration, and the swing mechanism can be rotated at a desired constant speed during coasting. This is achieved by controlling a hydraulic actuator adjusting the displacement of a variable displacement pump in different control modes, depending on a comparison between a desired displacement of the pump and an actual displacement of the same.

A series train of symmetrical dual rod-end double-action hydraulic cylinders with a cross sectional area in a series of powers of 2. The cylinders have corresponding computer controlled valves. The cylinders are switchable into three states. One state of shortcutting 2 fluid ports, another state of driving towards each opposite direction of reciprocation and the third state of idling. In the cylinder train all same polarity ports of the valve assembly are connected by hoses or pipes to align towards the same orientation to enable synchronous reciprocal motion and train power output.

A series train of symmetrical dual rod-end double-action hydraulic cylinders with a cross sectional area in a series of powers of 2. The cylinders have corresponding computer controlled valves. The cylinders are switchable into three states. One state of shortcutting 2 fluid ports, another state of driving towards each opposite direction of reciprocation and the third state of idling. In the cylinder train all same polarity ports of the valve assembly are connected by hoses or pipes to align towards the same orientation to enable synchronous reciprocal motion and train power output.

A closed-circuit, self-contained hydraulic axis includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that the cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic axis includes a main accumulator connected to the pump via first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic axis is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator.

A closed-circuit, self-contained hydraulic axis includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that the cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic axis includes a main accumulator connected to the pump via first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic axis is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator.

A regeneration device includes: a regeneration valve that controls the flow rate of an operating fluid being drained from one port of a cylinder; a non-return valve that allows a regenerative flow of the operating fluid from the regeneration valve to the other port of the cylinder and blocks an opposite flow of the operating fluid; and an exhaust valve that controls the flow rate of the operating fluid output from the regeneration valve being drained to a tank. The regeneration valve controls the flow rate independently of the exhaust valve.